The paleomagnetism and geological significance of Mesoproterozoic dyke swarms in the central North China Craton

The Mesoproterozoic mafic dyke swarms are extensively distributed in the central North China Craton(NCC) including North Shanxi, Wutai and Lüliang areas, which are not deformed and metamorphic but high magnetic, so the dyke swarms become the mark to compare the high metamorphic rock areas in magnetism. Based on the analysis of paleomagnetism of mafic dyke swarms in North Shanxi, Wutai and Lüliang areas, NCC inclined southward about 18ü so that North Shanxi lifted up and rotated 10ü left to Wutai area. The dyke swarms in Lüliang developed later than in North Shanxi and Wutai area. The NNW-trending and WNW-trending dyke swarms developed in Lüliang while the North China Plate moved northward consistently so that the paleomagnetism of dyke swarms in Lüliang is greatly different from North Shanxi and Wutai area.     

微机遥感图像几何纠正快速算法

本文针对遥感图像数据量大、微机几何纠正速度慢的问题,提出了一种微机遥感图像几何纠正快速算法。该算法采取了行列分离多项式快速运算、自动优化分块分配内存、多波段同时处理等措施,大大提高了运算速度,并且对任意大图像可一次处理,无需分块,使微机遥感图像几何纠正方法完全达到实用要求。文中阐述了算法的技术细节,介绍了算法在微机上的实现和其速度指标。     

无加密孤岛型DOM的制作方法研究

沿海地区远离大陆的孤岛因为条件限制,通常没有同一摄区孤岛区域的外业控制,即使有外业控制,但受内业加密条件的限制,无法与大陆摄区构成加密区域网,因此得不到孤岛的加密成果,给制作孤岛地区的DOM带来了问题。通过探索和实践,摸索出制作孤岛DOM的3种行之有效的方法。     

无加密孤岛型DOM的制作方法研究

沿海地区远离大陆的孤岛因为条件限制,通常没有同一摄区孤岛区域的外业控制,即使有外业控制,但受内业加密条件的限制,无法与大陆摄区构成加密区域网,因此得不到孤岛的加密成果,给制作孤岛地区的DOM带来了问题。通过探索和实践,摸索出制作孤岛DOM的3种行之有效的方法。     

TerraSAR-X数据验证几何纠正影像促进SAR立体影像匹配的可行性

随着SAR的快速发展,国内外学者对SAR的研究越来越深入,SAR立体提取DEM就是其中一个热点。在SAR影像立体提取DEM过程中,SAR立体像对的匹配结果直接关系到提取DEM成果的质量,尤其在地形起伏较大的山区,SAR影像匹配难以获得理想匹配结果。基于此情况,本文提出将基于影响模拟获取的几何纠正影像运用于实现SAR立体影像匹配的设想,并通过实验来验证其可行性。本文利用Terra SAR-X星载SAR数据进行了实验,并通过对实验结果进行统计分析证实了设想的可行性,为解决地形复杂起伏较大的山区SAR影像匹配困难问题提出了一种新思路。     

GIS空间数据的误差校正

主要介绍了图形输入过程中引起误差的原因,误差校正的原理及一和的误差校正方法,特别是在ＭＡＰＧＩＳ中应用的分块误差校正方法,实践表明效果很好,最后还简要地介绍了图形工的介。     

基于空间插值的影像纠正精度的空间可视化表达

现有影像纠正精度以控制点精度评定为基础 ,对于精度探讨采用可视化技术从整体上进行表达。以相似变换作为影像纠正的基本模型 ,推导了纠正后任意点精度与控制点精度的关系 ,并基于此选择采用距离倒数乘方法作为空间插值方法 ,插值影像纠正后任意点不同方向上的以及点位的精度。在此基础上 ,采用精度可视化的概念对影像纠正的质量加以描述 ,通过一个加密前后影像纠正的实例说明其应用的方法 ,并获得了一些有益的结论     

Misleading information from direct interpretation of Geometrically Incorrect aerial photographs

Remote sensing represents a powerful method to study the change of several phenomena over time. However, useful input data (for example, aerial photos) can produce misleading information if an inadequate geometric correction is applied. Among mathematical models used for this type of correction, orthorectification (differential correction) seems to be the only one that guarantees accurate results. However, many authors are still basing their results on incorrectly transformed images. This phenomenon is especially due to the incidence of several user-friendly tools and interfaces for the rectification of images. This paper tests both polynomial rectification and orthorectification. Aerial photography of 1954 of the same area was acquired and polynomial rectification and orthorectification were applied, using a 1998 orthophoto as a base. An unsupervised classification was performed by utilising the nearest neighbour method for the resampling of images. The area occupied by each class was calculated. A multitemporal analysis was then performed, considering the overlap between the 1954 orthophoto and the 1998 orthophoto as the base of reference. An overestimate up to 21% of class area was found. When multitemporal analysis was carried out, an overestimate up to 100% of class area change was found.     

一种航空影像快速纠正算法研究

在地理国情监测、农村土地确权等项目中,应用的航摄影像处理软件大多是后处理软件,这些软件往往存在精度高但处理效率不高的问题,而在灾害救援、重大突发事件应急处理等领域需要对航摄影像进行快速处理。本文所研究的算法正是针对这一问题,实现了无人机航摄影像的快速纠正,为应急事件快速指挥提供了高效的解决方案,具有一定的指导意义。     

依据点云强度校正的壁画纠正

壁画纠正能消除数字壁画影像的变形并赋予其空间参数特性,是壁画数字化保护中的关键步骤之一。激光扫描数据作为壁画影像与三维空间的媒介,在壁画影像的纹理映射和纠正中具有重要的意义。然而,激光点云强度的近距离反常现象给壁画纠正中特征点的提取带来了困难。本文针对基于点云的壁画纠正中强度信息的近距离反常问题,研究了激光成像原理,推导了顾及激光接收系统散焦效应的强度函数,并采集样本数据进行模型参数估计,通过对估计模型和实际采集数据进行比较,生成不受距离和入射角影响的相对反射率,从而有效校正了强度异常的点云数据。试验表明,在壁画影像纠正过程中,该方法能有效解决强度影像提取特征点少且分布不均的问题,效果明显优于通用的数字图像处理方法。